37 Questions
During cytokinesis, the cell divides into two by the process of
Mitosis
Which of the following structures is responsible for cytokinesis in animal cells?
Contractile ring
When does cytokinesis begin and end in the cell cycle?
Anaphase to telophase
Which part of the mitotic spindle in animal cells determines the plane of cell division?
The astral microtubules
What happens if the mitotic spindle is tugged into a new position in early anaphase?
The cleavage furrow disappears
In some cells, where is the site of contractile ring assembly chosen before mitosis?
In the cortex during a previous cell cycle
What determines the symmetry of cell division in most animal cells?
The placement of the mitotic spindle
Which of the following is true about asymmetric cell division?
It involves the segregation of fate determinants to one side of the cell.
What is the role of motor proteins in asymmetric cell division?
They help in the movement of the spindle within the dividing cell.
What is the function of the contractile ring in cytokinesis?
To generate the force for dividing the cytoplasm in two.
How does the contractile ring constrict during cytokinesis?
By decreasing its total volume and the number of filaments it contains.
Which type of mitosis is thought to have evolved separately from a common ancestor resembling the modern hypermastigote spindle?
Both open and closed mitosis
What is the purpose of cytokinesis in the cell division process?
To divide the cytoplasm of a single eukaryotic cell into two daughter cells
What happens to each daughter cell after the completion of telophase and cytokinesis?
They enter the interphase of the cell cycle
Which structure guides the assembly of the cell plate during cytokinesis in higher plant cells?
Phragmoplast
Which protein is responsible for the recruitment of all other cell division proteins to the division site in bacteria?
FtsZ
Which protein has apparently taken over the function of FtsZ in mitochondrial division in fungi and animal cells?
Dynamin
What is the purpose of the preprophase band in higher-plant cells?
To determine the exact position and orientation of the cell plate
What is the first visible sign that a higher-plant cell has become committed to divide in a particular plane?
Formation of the preprophase band
How does binary fission in procaryotes differ from cytokinesis in higher plant cells?
Binary fission depends on filaments made of the FtsZ protein
In which organisms does mitosis depend on a membrane-attachment mechanism, where the chromosomes have to bind to the inner nuclear membrane for segregation?
Dinoflagellate Cryphthecodinium cohnii
In which organisms does the spindle remain outside the nucleus and press on the outside of the nuclear envelope during mitosis?
Hypermastigotes
Which organelles cannot assemble spontaneously from their individual components?
Endoplasmic reticulum
What happens to the actin filaments in the contractile ring when microtubules are depolymerized?
They become less organized
What is the role of Rho A in cytokinesis?
It stimulates actin polymerization
How are membrane-enclosed organelles segregated when a cell divides?
They hitch a ride with spindle microtubules
Which phase of the cell cycle is characterized by DNA replication?
S phase
What is the main function of the G2 phase of the cell cycle?
Cell growth
Which phase of the cell cycle is responsible for nuclear division?
M phase
What is the purpose of cytokinesis in the cell cycle?
To divide the cytoplasm
During which phase of the cell cycle does DNA synthesis occur?
S phase
What happens during the G1 phase of interphase?
The cell increases its supply of proteins and grows in size.
What is the purpose of the G0 phase in the cell cycle?
Stop cell cycle and enter G1 phase for undergoing differentiation.
What are the four phases of the eukaryotic cell cycle?
G1 phase, S phase, G2 phase, M phase
Which of the following best describes the cell cycle in eukaryotic cells?
A series of events that causes a cell to divide into two daughter cells
What are the main stages of the cell cycle in eukaryotic cells?
Interphase and the mitotic (M) phase
How is the cell cycle in prokaryotic cells different from that in eukaryotic cells?
Prokaryotic cells have B, C, and D periods instead of interphase and the mitotic phase
Test your knowledge on FtsZ, a cytoskeletal GTPase that plays a crucial role in cell division. Explore its structural similarities to tubulin and its assembly into a ring at the cell equator. Learn about the significance of FtsZ filaments in recruiting other cell division proteins and the formation of a septum.
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